“What hasn't been available for sound is the sort of materials you need to build a cloak out of.”

Sonic crystals

The scientists seem to think that the answer for the cloak’s material comes in the form of sonic crystals. "Unlike ordinary materials, their acoustic properties are determined by their internal structure," says Professor Pendry about the meta-material.

If they crack the commercial market with the ‘acoustic cloak’ there could be plenty of use for the material. On top of the list is the Military who could use it to conceal submarines, but it could also be used in the home to get the Environmental Health of your back for noise pollution.